Boeing pauses 777X flight tests after engine mounting structure failure

The US Federal Aviation Administration also ordered inspections of cockpit seats on Boeing 787s after Latam plane's mid-air dive in March

A Boeing 777-9, a variant of the 777X wide-body. Flight tests began in July. Reuters

Boeing is halting 777X flight tests after an inspection revealed the failure of a structure that mounts the General Electric engines to the massive aircraft's wings, in the latest setback to the long-delayed programme.

The cracked thrust link was found on a 777-9 aircraft during routine maintenance after a test flight.

“During scheduled maintenance, we identified a component that did not perform as designed,” Boeing said in a statement on Monday. “Our team is replacing the part and capturing any learnings from the component and will resume flight testing when ready.”

The US plane maker also said it is keeping the Federal Aviation Administration “fully informed” on the issue and had shared information with its customers.

The part in question is a component between the engine and the structure of the 777-9 variant of the jetliner.

“We are inspecting the flight test fleet for this condition. No near-term flight tests were planned on the other flight test airplanes, which have scheduled maintenance and lay-up activities,” Boeing said.

The discovery is the latest delay to Boeing's efforts to certify the 777X wide-body aircraft that is running about five years behind schedule.

The US plane maker began flight tests with US aviation regulators on board in July, marking a key milestone for the 777X programme.

In July, Emirates president Tim Clark said he was expecting the first of the airline's 205 Boeing 777X aircraft to enter service by 2026, after attaining full certification at the end of 2025.

Boeing would face heightened regulatory scrutiny of its new wide-body jet and must ensure it got it right, Mr Clark told reporters on the sidelines of the Farnborough International Airshow in England in July.

Emirates and Qatar Airways are among the Middle East's biggest customers the 777X.

Qatar Airways placed an order for an extra 20 Boeing 777-9 jets at the Farnborough show, taking its order book for the 777X family of aircraft to 94. The Doha-based airline now has 60 Boeing 777-9 passenger aircraft on order.

The pause in 777X flight testing may have "a significant impact" on the timeline for the aircraft's entry into service, according to Linus Bauer, founder at aviation consultants BAA & Partners.

"Flight testing is a critical phase in the certification process, and any interruption can cause delays. Given that the 777X has already faced multiple delays, this halt could push the programme further behind schedule," he said.

The delay could also exacerbate Boeing's existing challenges, including navigating a complex regulatory environment, raising concerns because the 777X is a cornerstone of the company's long-term strategy for the wide-body market, Mr Bauer said.

787 Dreamliner inspections

Also on Monday, the FAA issued an airworthiness directive requiring operators of Boeing 787 Dreamliners to inspect the aircraft's cockpit seats, following reports that their inadvertent movement had disrupted flights.

The directive follows an incident in March when a Latam Airlines plane went into a sudden mid-air dive that injured more than 50 passengers.

“The FAA has received, with increasing frequency since March 2024, reports of uncommanded horizontal movement of the captain’s or first officer’s seat when occupied,” the US regulator said in a filing.

“Uncommanded horizontal seat movement can cause in-flight upset from unintended and abrupt flight control inputs, which could result in a rapid descent of the airplane and serious injury to passengers and crew.”

The directive relates to pilot seat rocker switch caps which are responsible for the seats' movement.

The US government agency said airlines flying Boeing's 787-8, 787-9 and 787-10 aircraft should inspect these seat switches.

Boeing, in a separate statement on Monday, said it fully supports the FAA airworthiness directive.

The 787 Dreamliner inspection will be "frustrating for customers and costly for Boeing", Mr Bauer said.

These issues come as Boeing's new chief executive Kelly Ortberg completes nearly two weeks on the job after starting his role on August 8.

Mr Ortberg pledged to “restore trust” in the embattled US aerospace company when he officially took charge.

Issues such as the 777X flight test delay or the 787 inspections are likely to pose a challenge for the new leader.

"Any further delays in high-profile programmes like the 777X could undermine confidence in Boeing's leadership and technical capabilities. [Mr] Ortberg's ability to navigate these issues will be critical in restoring stakeholder confidence and securing the company's future," Mr Bauer said.

"Both the 777X and 787 issues represent significant hurdles for Boeing, affecting its financial performance, customer relations, and industry reputation. For the new CEO, addressing these challenges effectively will be crucial to restoring Boeing's standing in the global aviation industry."